The present invention relates to a remote-control-light detecting device for an AV (audio-visual) apparatus, and particularly relates to a photo-detecting device having an improved remote-control-light receiving portion provided in a front panel of an AV apparatus.
Recently, remote control devices have become popular by which a viewer or listener can perform, from a position away from an apparatus such as a TV receiver, a stereo apparatus, etc., operations such as power on/off operation, sound volume increasing/decreasing operation, channel change-over operation, and so on, bringing much convenience in carrying out those operations of the AV apparatus.
In many of such remote control devices, an operation signal is transmitted to an apparatus to be controlled in the form of modulated infrared light. A portion for receiving the infrared light is provided in a front panel of the apparatus. As shown in FIGS. 8 and 9, a plane transparent portion 2 is provided in a front panel 1, and light such as infrared light transmitted through the transparent portion 2 is made incident directly (FIG. 8) or through a glass fiber 4 (FIG. 9) upon a photo-detecting element 3 which is part of an operation command system provided on a printed circuit board.
Photo-detecting devices of such remote control devices have the following problems Since the photo-detecting device has a plane light-receiving surface, in order to make remote control light incident accurately upon the light-receiving surface from any position in a wide angular range, it is necessary to make the area of the light-receiving surface large. To this end, a relatively wide area of the light-receiving surface must be secured in spite of the limited area of the front panel of an AV apparatus. It is therefore unavoidable to sacrifice areas for the rest of the operation system and a display system. Specifically in a small AV apparatus such as a mobile apparatus, the front panel is very narrow in area, so that the size of the light-receiving surface remarkably sacrifices areas for the other system such as a display system.
Further, in remote control operation, it is necessary to make remote control light incident upon the light-receiving surface substantially perpendicularly. There has been therefore a case where no response is obtained to an operation performed from a direction slanting relative to the front panel.